New details emerged Thursday in police-involved shootings that left one man dead in Southwest Baltimore and another wounded in Northwest.

In a span of less than two hours Wednesday night, Baltimore police officers killed a man they said appeared to be impersonating an officer during a burglary and wounded another man they said robbed a convenience store.

The Police Department credited the officers with quick responses that stopped two crimes in progress, a priority for commanders who have stepped up patrols amid a 50 percent increase in homicides so far this year.

The incidents were the city's third and fourth police-involved shootings this year; two have been fatal. The identity of the man killed Wednesday has not been released. Police said officers shot him after he pulled out a gun at a robbery scene.

Last year, six people were killed and nine wounded in police shootings.

Police said they did not find a weapon on the suspect in the Northwest Baltimore convenience store robbery but believe the officer was justified in firing on the man because she believed he was armed and he was not following orders.

As a snowstorm bore down on Baltimore about 8:15 p.m Wednesday, a Baltimore police officer saw a 7-Eleven cashier with his hands in the air as she drove by the store.

A man wearing a black jacket and black pants with his face covered had threatened the clerk, indicating that he had a gun, said Sabita Dhakal, a co-worker at the store in the 2500 block of Liberty Heights Ave.

The officer moved in as the suspect left carrying the store's till in his hand, police said.

Police spokeswoman Sgt. Sarah Connolly said the man did not comply with the officer's orders, and she fired two shots, wounding the man. He was taken to an area hospital.

Police said the suspect matches the description of a suspect from a robbery just 15 minutes earlier on Cold Spring Lane, and said he hinted to the 7-Eleven clerk that he had a weapon in his pocket. None was found at the scene.

"He just grabbed the till," Dhakal said. "It didn't seem like he had any weapon with him. We checked the video in the morning and saw that."

Dhakal said store operators didn't know how much was in the register.

Police will launch routine internal investigations in both incidents, and the officers involved will be placed on paid leave under department policy.

In the 7-Eleven shooting, Connolly said it appears the officer presumed the suspect had a weapon because she saw the clerk with his hands raised in the air.

"Obviously in this case, the officer believed that the individual had a handgun," Connolly said. "If you feel that you're in danger or someone is in danger around you, you have to use whatever force is necessary to keep a felony from happening or to keep those around you safe."

Lance LoRusso, the author of "When Cops Kill" and a former officer who serves as a police union attorney in Georgia, said officers do have a right to shoot if they have a "reasonable subjective belief" that a suspect is armed.

In this case, he said, the fact that the clerk had his hand up indicates that a weapon might be involved. Convenience stores are also known as locations for stickups — another factor that may cause an officer to presume a suspect is armed.

John L. Burris, a California lawyer who represented Rodney King in his civil case, said it's not unreasonable for an officer to believe that the suspect was armed based on the clerk's hoisted hands.

"It may be a justifiable shooting, but on the face of it, I'd probably want to know if there were any independent witnesses," he said. "Independent witnesses are a tiebreaker. Police already have a version that's going to satisfy their base."

At 10:52 p.m., officers responded to a home in the 1800 block of Spence St. in Southwest Baltimore's Morrell Park neighborhood for a report of a burglary. As they entered shortly before 11 p.m., officers saw signs of a burglary in progress and encountered two people. Both wore clothes that had the word "police" on them.

Police said one of the men had a gun, and the officers yelled several times at him to drop his weapon before both officers shot him. The man, who was not identified, was pronounced dead at a hospital shortly after. No officers were injured.

Detectives believe the men broke into the home but did not impersonate police to gain entry, Connolly said.

Police are not releasing the names of any of the suspects or the officers who fired at the suspects. Their names will be released 48 hours after each incident, which is Baltimore police policy.